Form of internal-combustion engine



G. K. DAVQL FORM 0F INTERNAL GOMBUSTION ENGINE Jan. 17, v.19218e Filed Jan. s, 1925 4 Sheets-sheet 1 INVENTOR.

ATTORNEYS.

Jan. 17, 1928.

G. K. DAVOL FORM OF INTERNAL COMBUSTION ENGINE- Fillebla.. leg 1925 4 Sheets-Sheet 5 INVENTOR.

Jan. 17, 192s. 1,656,884

cs. K. Avo| V FORMOF INTERNAL GOMBUSTION ENGINE Filed Jan. 5, 1925 4 Sheets-Sheet 4 FIG. 5

` INVENTOR.

/c. TIE* f dit 2W 4 r ATTORNEYS.

Patented Jan. 17, 1928.

UNITED STATES PATENT OFFICE- GEORGE K. DAVOL, OF SAN FRANCISCO, CALIFORNIA; PHIL C. KATZ ADMINISTRATOR OF SAID GEORGE K. DAVOL, DECEASED.

FORM OF INTERNAL-COMBUSTION ENGINE.

i Application led January 5, 1925.

My invention consists of a combination and arrangement of parts, which has the effect of producing a very compact and small engine of light weight for the power pro.

duced, as well as an engine that can be manufactured at an exceptionally low cost. My invention not only produces a small, compact and light engine for the power produced, but also a form of engine that is l0 particularly adapted for certain purposes Where space is restricted.

My invention has to do with that class of internal combustion engines which employs opposed pistons, or two pistons reciprocating in opposite directions in one open ended cylinder, and is particularly concerned with the manner of transmitting the movement ofthe opposed pistons to the revolving shaft of the engine.

My invention is not concerned with the manner of introducing the fuel into the cylinder, or with the ignition of the fuel, and it is applicable to either the fuel injection, or Diesel type of engine, or to the gas, or carburetting engine.

More particularly, my invention is embodied in an engine having a main shaft with two inclined crank pins whose axes are inclined at an angle to, and intersect the main axis of the shaft. On each of these inclined crank pins, 'a Wabbling member is loosely or revolvably mounted. but prevented from turning with the shaft by suitable means. Arranged parallel to and surroundinclined crank pins are a number (preferably four) of open ended cylinder-s, each cylinder having two pistons reciprocating in opposite directions within it. Suitable connections between each of the said pistons and one of the said wabblin'g members serves `to complete the transmission of movement of the pistons to the shaft.

One of the important features of mylinvention lies in the arrangement of parts whereby the reaction of the thrust of the two pistons in opposite directions, in any one of the cylinders, is taken by two thrust bearings on the main shaft, so that the effect of the two opposed thrusts is to produce a longitudinal tension in the shaft. The frame of the engine is Arelieved in this manner of the necessity of reacting against these thrusts.

ing the shaft and disposed between the two Serial No. 537'.

`For more detailed description of my `inyention, I refer to the accompanying draw- 1n s, in which:

ig. l, shows a longitudinal section of a two cylinder engine, embodying my invention, the section being taken in the plane of the axes of the cylinders and shaft. For the sake of clearness, this figure is made to some extent diagrammatical.

Fig. 2, is a partial longitudinal view of a a four cylinder engine, taken` in the plane of two of the cylinders and the shaft, and silovting only one half of the cylinders and s a Fig. 3, is a cross sectional View, taken in a plane perpendicular to the axis of theshaft of a four cylinder engine, looking towards the open ends of the cylinders, or on line 3/-11/ in Fig. 2.

Fig. 4, is an end view of one of the parts designated as Wabbling knuckles taken in a pla-ne perpendicular to the axis of the knuckle, or to the aXis of the crank pin.

Fig. 5, is al longitudinal plan view, with the upper part of the cylinder holding body removed, and is intended particularly to show the arrangements provided for operating the fuelA valves, or for operating starting valves, or other devices which require cyclic operation.

All parts shown and referred to are given the same reference numbers in all the drawings.

Referring to Fig. 1 the main frame (l) carries a cylinder holding body (2) which is preferably made in two parts. In this ca-se there is one cylinder vin each part, one above and one below and both parallel to the shaft. The shaft (3) passes through the cylinder holding body along the junction or joint between the upper and lower parts.

As shown in the drawing the cylinders are bored directly out of the cylinder holding body (2), and that part might properly be said to constitute the cylinders, but I prefer to refer to it as a cylinder holding body, as it may be advantageous to form the cylinders themselves of separate tubular parts, which may be inserted in and held in place by this cylinder holding body. It will be understood that in this description, and in the claims which follow, this part, referred to as a cylinder holding body, may constitu'te the cylinders themselves, or a part in which the cylinders proper are inserted and held. 4

The shaft (3) is carried in bearings (4) in the cylinder holding body, and in bearings (5) in the main frame (1).

Those portions of the shaft between the end bearings (5) and the cylinder holding body comprise cranked portions, or crankpins (6), one at each end of the shaft. These cranked portions of the shaft, or crank pins, have their axes inclined at an angle to the main axis of the shaft, and are preferably formed in the same lane.

Mounted on each of these cran pins, or crank portions of the shaft (6), 'is a -part (7) which I term a Wabblingknuckle This Wabbling knuckle is preferably made in halves joined in a suitable manner, so that they can be put in place to embrace and ride upon the crank pins (6) on which they have a suitable running fit.

The Wabbling knuckle at one end of the engine is shown in Fig. 1 .in section', While the knuckle at the other end is shown in side view, with the interior chambered portion shown by..dotted lines. stood that these two knuckles are intended to` be identical, in form Aand construction,`

as Well asl are the `thrust bearings Within them. y

-These Wabbling knuckles (7) While riding loosely on the crank pins (6) are prevented from turning with the revolving .shaft and crank pins, by any suitable i the cranked portions of the shaft (6), or the crank pins, intersect the main axis of the( shaftat the points (11). The axes of the pins (9) on which the sliding blocks (8) are mounted should also ass through these same points (11). If t is arrrangement is aceuatcly carried out, the blocks (8) can be mounted on the cylindrical pins (9), but if theaxes of the pins (9) do not intersect the points (11) then a universal movement Will have to be provided for between the blocks (8) and their points of attachment to the wabblin knuckles (7).

In eac of the cylinders, two pistons (12) and (13) reciprocate. l The pistons (12) at one end of the cylinders, uncover or override the inlet ports 14:) at the outer ends of their strokes, an kthe pistons (13) at the other ends of the cylinders' uncover or It will be underf vpistons (13) and the gases within the cylinder permitted to escape. The inlet or scav enging ports are then uncovered by thc pistons (12), and the scavenging air under pressure enters the cylinder through the ports (111), as indicated by the arrows in Fig. 1.

The pistons at one end of the engine are all connected to the Wabbling knuckle at thatend of the shaft by means of the connecting rods (16). These rods have connec- .tion to the pistons through ball and socket joints, or some equivalent arrangement, permitting universal movement..- In Fig. 1,

the ball is formed on the end of the rod,

in the end of the rod and the ballon the part (17) which is secured to thepiston.

The outer ends of the rods, which engage with the Wabbling knuckles, do so through ball and socket joints, as shown in Figs. l1 and 2. .Any suitable equivalent arrangement, permitting universal movement, can be employed.

If the shaft (3) be revolved, the Wabbling. knuckles,'carried on the cranked portions (6) of the shaft, and prevented from turn in with the shaft by the sliding blocks (8%, will be given a Wabbling movement, which, through the connecting rods (16), imparts a reciprocating movement to the pistons With which they are connected. In actual operation this action is reversed and the reciprocating movement of the. pistons cause the shaft to revolve.

The thrust of the pistons, through their connections against the Wabbling knuckles, is eounteracted by the thrust bearings or collars (18) Whichare formed, or mounted rigidly on the crank pins, or cranked portions of the shaft. The pressure of the two Wabbling knuckles against the thrust bearings on the shaft, constitutes two e ual and op osed forces which balance eac other, an produce a tension in the center portion of the shaft.

The thrust bearings on the cranked portion of the shaft shown in Fig. 1 are there shown in the elementary form of plain faced collars 18 against which the inside face of the Wabbling knuckles 7 directly bear. This serves to illustrate in the most simple form the function of the bearing and thecooperawhile in Fig. 2 the socket is shown formed i tion of parts. In a practical working design however, it is very essential that a form of thrust bearing be provided, that will continuously sustain the bearing pressures exerted by the pistons against the wabbling knuckle without undue heating and without failure.,

In an engine operating on the two-stroke cycle for which my invention is primarily intended, the pistons always exert an outward force, in the form here described, a continuous force against the wabbling knuckles, and this forcefrom the combined action of four pistons as illustrated in Figs. 2 and 3, is very great, and has to be counteracted by the thrust bearing and so transmitted to the shaft.

The practical success of this type gine, particularly in medium and large sizes,

` is therefore largely dependent upon the use of a form of thrust bearing capable of continuously holding up under this very severe service. I do not consider in large sizes, any form of ball or roller thrust bearing suitable, while the plain collar type of thrust bearing in this application would be entirely unsuitable.

I have therefore provided, combined with and housed within the wabbling knuckle, a thrust bearing comprising a number of separate, pivotailly or universally supported shoes, which together take the end or axial thrust of the wabbling knuckle and transmit it to thethrust collar formed on or secured to the crank pin.

In Fig. 2, I have shown in elementary form such a type of thrust'bearing. Here I have shown separate bearing shoes 19 spherically formed on their backs and carried in sockets 2O attached to the wabbling knuckles, thus providing for each bearing shoe a support permitting a universal movement and so allowing the shoe'to adjust itself to the forms bearing on it.

For the sake of simplicity, I have omitted in the drawing the equalizing devices such as are commonly embodied in bearings of this type, whereby the total pressure on the bearing is cqualized among the separate shoes employed, even though the parts, constituted in this instance by the knuckle and thrust collar, may not runA exactly true or coaxially. In actual practice such equalizing devices would be provided.

This form of bearing not only shows small frictional losses, and can continuously function under the heavy loads which this application imposes, but also permits of the use of a split thrust collar 18 or one made of halves and clamped around Vits seating on the shaft or crank pin, which is the intended manner of holding the collar 18, as shown,

in place. This allows the making of the crank pin in one piece with the crank arms, v

which form of construction could not be adof en- Y Itis preferable that the axes of the crank pins (6), or the axes of the wabbling knuckles intersect the main axis of the shaft, as indicated in the drawings, Figs. 1, 5 and (i, and also that the axes of the pins (9) carrying the sliding blocks (8) intersect the axis of the-shaft at the saine point, as indi; cated in Fig. 1, but this exact intersection of these axes is not absolutely essential, as a limited deviation from exact intersection is allowable, if the attachment of the sliding blocks (8) to the wabbling knuckles allow for universal movement.

It is also preferable that the points of connection of the connecting rods (16) to the knuckles (7). all lie in a plane perpendiculaito the axis of the crank pin and passing through the point; of intersection of the axis of the crank pinwith the axis of the shaft, as shown in Fig. 1.

In engines of this type, in which open ended cylinders are arranged parallel to the shaft and betweentwo wabbling members carried on inclined crank pinsV at opposite ends of the shaft, and lhaving in each cylinder two oppositely reciprocating pistons connected to the wabblingzmembers, the sha-ft should properly be required to meet a numiber of conditions, all of which have not heretofore in an discloseddesign, been coinpletely or properly provided for.

I wish here to explain that in this specification and in the claims that follow, when referring to the crank pins 6". and the wahbling knuckles 7, I use the term outer to designate the direction towardv the end of the engine or away from the cylinders, and the term inner7 to designatethe opposite direction, or toward the cylinders or center of the engine. These terms as applied are to be so understood.

The form of shaft which my invention dis closes, and which is shown in Fig. 1,.I claim as being distinctly different from' shafts heretofore suggested for or employed` in engines of this type, and that it is particularly7 designed to care for the conditons and requirements listed below.

First: It is very important that the Ainclined crank pins be long enough to permit the bearings of the wabbling knuckle boing spaced far enough apartto avoid excessive pressures on them, due to the tilting. action of the thrust of the pist-ons on the knuckle, and also long enough to provide for proper length of the knuckle bearings and for the thrust bearing parts between them.

A diagram of forces will disclose, that` for a given length of crank pin, or for a given llo of the cylinder, the less will be the maximum and the average pressures on these bearings of the wabbling member on the pin.

In the form of shaft I provide, the crank pins are long and the point ofintersection l1 with the 'shaft axis is toward their inner ends, so placing the outer bearing of the wabbling knuckle on the pin, a considerable distance from the shaft axis, and close to the cylinder axis, while the inner bearing is close to, or as shown in the drawings, almost centers on themain shaft axis.

'lhis lmanner of reducing bearing pressures on the crank pin mayl be carried out to a greater degree than by the proportion of parts shown in Figs. l and 2. The crank pins and shaft may be so'designed, for example, that the entire crank pin may lie to one side of the shaft axis, and the intersection of the axes of the pin and shaft would then come on a continuation or extension of the crank pin axis inwardly beyond the inner bearing on the pin. Such proportions and arrangement would, of course, increase the throw of the outer end of the cra-nk pin, and with the same length of pin as shown in Fig. 2, for example, would have the effect of reducing the bearing pressures on the pin below thatwhich results in the proportions and arrangement shown in Fig. 2.

It is to be understood therefore that the intersection of the axes of the pin and shaft need not necessarily lie on the pin itself as shown in Fig. 2. y

The final and best proportions of these parts for any engine will be arrived at with due consideration being given not alone to bearing pressures but to other features and values as Well.v -f' Second: A very heavy tension is produced in the shaft by the opposed thrust of the pistons acting on the wabbling knuckles and being taken by the thrust collars 18, and it is importantthat thistension be transmitted as directly as possible through the shaft, from one thrust collar to the otherrat the opposite end of the shaft.

In the form of shaft which my invention provides, this tension is not transmitted through any offset crank arm, required thereb 1 to sustain bending stress, but in a very irect line, as shown in Fig. l through the centerportion of -theshaft and the two'l massive wedge shaped blocks connecting the center portion of the shaft to the two crank pins. AThis results in the practical ellnination of bending stress in theshaft due to this tension.

Third: vIt is very desirable in an engine of this type that the cylinders be placed as closely to the shaft as possible. 'This reirders the engine compact, light, and economical of construction, and. for a given length of stroke, lessens, the bending moment on the shaft due to the thrust of the pistons.

It is however, very desirable to provide for the withdrawal of any one of the pistons when that point on the wabbling knuckle which it is connected to is at the outer end of its swing or stroke, and if the inner crank arm or the crank arm nearest the cylinder is made long, it interferes with the withdrawal of the piston when the knuckle is in this position.

With the form of shaft I provide, carr ing crank pins the outer portions of whic 1, measuring from the point of intersection ll of their axes with the axis of the shaft, are much longer than their inner portions measuring from the same point, the inner crank arms become either exceedingly short or are entirely absent, and the pistons on being` withdrawn have only to clear the Wedve shaped cylindrical part which serves as tie inner crank arm, or as a means of uniting the center portion of the shaft with the crank pin. This permits of placing the cylinders as closely to the shaft as other conditions will allow. This feature is of particular importance in engines of short stroke relative to cylinder bore. n i

Fourth: As before stated, it is very desirable, if not absolutely necessary, for practical results of this type, to use the separately supported shoe type of thrust bear ing for taking the actual thrust of the Wab bling member on the crank pin. Such bear ings have thrust collars of large diameter. AThis is indicated in Fig. 2 where the thrust collar 18 is shown in approximately reasonable proportion to the size of cylinders shown. These thrust collars, if made ,in halves, also require a considerable space on the shaft or pin on which they are clamped or seated, the length axially being commonly made equal to about onethird of their outside diameter. The bearing shoes and shoe supporting devices also require a space approximately equal in diameter to that of the thrust collar and of considerable length axially.

It can be seen that the proper accomrnof dation of these bulky parts, without encroaching in the space required by the ball sockets 28 and the retaining rings 34: oifers considerable difficulty, especially in short stroke engines, in which the ball sockets 28 are proportionately large with reference to their distance from the crank pin axis. ItV

is also an advantage that no projection of large diameter extend inwardly, or toward the cylinders, on the crank pin axis much beyond the plane of the ball sockets 28.

The construction disclosed in Fig. 2 overcomes these diiiculties by providing for set- Ell Ilm

' short stroke engine, and also accommodates the bearing shoes and shoe supporting devices witliout a projection of their housing, formed by the knuckle 7, inwardly toward `the cylinders beyond the plane of the ball sockets 28.

The proper carrying out of this arrangement requires that the crank pin be so placed that the point 11 of intersection of its axis with that of the shaft is closer to its inner end than to its outer end, as shown in Fig. 2.

The design of shaft I provide by which all the Aconditions and requirements above listed are properly met, results in an unbalanced crank pin,or a considerable revolving mass centering at the outer end of the crank pin, and including a portion of the wabbling knuckle, a portion of the crank pin and a portion of the outer crank arm. This'revolving mass can be largely balanced by a counterweiglit 33, attached to an arm extending diametrically opposite to the outer Vcrank arm.'

This manner of applying the counterweight however, results in an unbalancedrevolving moment produced at each end of the shaft, as each mass revolves in a plane separated some distance from the plane in which its counterweight revolves, but in as much as these revolving moments of equal force and of opposite direction yare produced at each end ofthe shaft they cancel each other.

-In the construction shown in Figs. 1 and 2, which is mypreferred construction, par ticularly for large engines, it is essential that there be very effective lubrication. of the thrust bearings. To this end, I form a hollow chamber in the wabbling knuckle l' (7) between its two bearings on the crank pin, or cranked portion'ofthe shaft, and within this chamber I locate'the thrust bearing. Means are then provided to conduct lubricant to this chamber in ample and sufi, cient quantity. Such means are indicated* in Fig. 2, where there is shown by dotted lines, a bored passage (24), entering on the axis of the shaft at its end, and communicat- -ing with the chamber within the wabbling knuckle (7). Through this passage lubri` cant is supplied to this chamber, and to the thrust bearing withinr it, and at the same time, to the bearings of the wabbling knuckle on the crank pin (6). This hollow construction of the wabbling knuckles (7), with the thrust bearings (18) located within and enclosed by the chamber so formed, is important.

Other means or passages may be employed Jfor getting the lubricating oil into the in terior chamber of the wabbling knuckle, if desired. It is essential that lubricating oil be conducted into thisv chamber in sufficient quantity to not only supply ample lubricant to the thrust, and to the end bearings of the knuckle, but also in suiiicient quantity to serve as a cooling medium capable of .carrying oil' the excess heat generated through the friction of the thrust bearing. To this end a continuous circulation of oil -should be maintained into and out of the knuckle,

the oil being supplied in sufficient quantity and allowed to leak out through the end bearings and through other passages if necessary, in order to maintain such a circulation.

Any number of cylinders may be employed in an engine of this design that may be found convenient. Four cylinders have been found to constitute a practical design, and in Fig. 3 I show a cross section showing the arrangement of four cylinders. As here shown, two cylinders are formed in the upper half, and two cylinders in the lower half of the cylinder holding body (2), and bearings for the shaft are formed between the two halves. The lower half of the cylinder holding body rests on the base plate (25); and side plates (26), are provided,

vwhich are secured to the cylinder' holding `body on each side, and which extend to and are attached to the end shaft bearings (27), as shown in Fig. 5.

The side frames 26 together with the base plate 25 to which they are properly secured, 1

form, together with the end bearino' supports, a box shaped girder of great stiffness. As shown in the drawings, the end bearing supports are vmade integrally with the base plate 1, but in practical construction, par

ticularly of large engines, it will be preferable to make the end bearing supports -separate from the base plate.

This construction results in a very 'strong and rigid support for the main shaft bearings, which are so maintained rigidly in line` while at the same time the shaft is readily accessible. Removal of the ymain shaft is readily accomplished through the loosening and lifting olf of the upper half of the cylinder holding body 2 and removal of the caps of the end bearings, when the shaft may be lifted out. This construction also permits the removal of either side frame 26 without disturbing the othervmain parts,

vwhich for purposes of overhauling, is a coiisiderable practical advantage.

As my invention is primarily intended to be carried out in an engine operating on 'atA the two-stroke cycle an even number of cylinders can be, an preferably should be iemployed. This ermits of placing onehalf the cylinders in the upper and one-half in the lower halves of the cylinder holding body or housing 2, symmetrically arranged with reference to the dividing plane. This is for structural reasons important, and

would not be possible with van odd number of cylinders which an engine operating on the four-stroke cycle would require, if regularity of impulses was preserved.

All references to cylinders hereinbefore are intended to apply to working cylinders or engine cylinders in which the working gases expand'and all references to cylinders in the claims whichiollow are to be so understood. Itis, of course, possible to add, where space permits, cylinders having other functions, such as for the compression of air or pumping of iuids, which additional cylinders may contain pistons operated from the wabbling knuckles, but cylinders of this nature are not considered herein.V

As shown in Fig. 3, the guides 10, for the sliding block (8) are attached to the base plate (25), and are. centered on a plane passin between the lower cylinders.

In 2 ig. 4, I show an end view ofthe wabbling knuckle (7), used for a four cylinder engine, showingA the four sockets (28) for the reception of the ball ends of the-connecting rods (16), and also showing the sliding block (8), mounted on the pin y,(9), at the bottom. As here shown, the wabbling knuckle is made in two halves, united by a flanged joint and bolts. i -f This construction of the wabbling knuckle 7 in halves is an essential to my design as a whole, asit not only permits the making of the inclinedcrank pins integral with the crank arms at each end of the crank pins, but also permitslof `complete access to the hrust bearing located within .or embraced y it. K i

In the ractical construction and 'operation of this type of engine in moderateand large sizes, it is essential that the separate shoe type of thrust bearing, which is the preferred type of thrust bearing to employ for this service, be completely accessible, for assembly in place, orfor overhaul, inspection, removal or adjustment; without interference from the part which embraces and eneloses it when in operation, and for this alone it is most important that the wabbling knuckle be made in two completely separate halves.

For the operation of the various valves, such as the fuel injection valves, starting air valves, or other devices connected with the workin cylinders, which require cyclic operation, I provide the valve gear vshafts (29), shown in Fig. 5, which reCeive motion from the main shaft (3) through the gears (30). These shafts have a bearing in the end bearings (27), and lie arallel to the niain shaft (3). They pass t rough one end of the cylinder holding body (2), as shown in Fig. 5, and also in Fig. 3, and reach to 'the vicinity of the center of the cylinders. In the case of the four cylinder design two of such valve ear shafts are provided, one on each side of the engine, each shaft serving to operate the gear connected with the two cylinders on its side of the engine. 'lhcy are suitably supported in bearings where necessary, as in the bearings (31) in Fig. 5, and can be provided with cams (32), or other /devices for operating the valves, etc.

I prefer the construction in which two pistons reciprocate in one straight and continuous cylinder, open at both ends, but it must be recognized that this exact construction is not essential, as instead of one straight and continuous cylinder being employed for the two co-operating pistons, two cylinders, whose axes may not exactly coincide, may be employed, with one of the two co-operating pistons reciprocating in each cylinder, and the two cylinders'connected at their inner ends, so as to form one central compression j space, common to both cylinders. With this construction, the exhaust orts would be formed in one cylinder, an the inlet ports formed in the other cylinder, and as each pair ofcylinders would be connected, their loperation, would be the same as if one conter modifications, while unfavorably aii'ecting the balance of the engine, do not affect the essence of my invention, and it must be recognized, that in these speciiications and in the claims which follow, any reference to a cylinder in which two pistons reciprocate, is intended to cover any such equivalent construction in which two separate cylinders, whose axes may even not exactly coincide, but which are connected to a common coinpression space, are employed.

It must also be recognized that while I prefer the construction in which the axes of the cylinders are parallel to the main axis of the shaft, the cylinders may be set with their axes not exactly parallel to the axis of the shaft, within certain restricted limits, without materially affecting the operation desired. Any such, limited deviation frein exact parallelism between the axes ofthe cylinders and that of the shaft, does not affect the essence of my invention, and is intended to be allowed for and covered in the claims which follow, by the expression substantially parallel.

Although it is preferable, for the sake of perfect balance of the reciprocating parts, to have the two crank pins, or the two cranked portions of the shaft in thesame plane, this exact arrangement is not essential, but, if desired, the two cranked portions of the shaft may lie in different planes, separated by a small and limited angle, so that one of each pair of co-operating pistons may have a lead over the other piston. This arrangement may, if desired, be utilized to modify the relative timing of the opening and closing of the exhaust and inlet ports in any one cylinder.

rll`he tern'1"wabbling knuckle by which, in these specifications and in the claims which follow, I designate that part mounted on the cranked portion of the shaft and against which the pistons thrust, need not beregarded asan inherently descriptive term, butas an arbitrarily selected term, used to designate the part referred to. The part must necessarily have a wabbling move# ment, and it resembles to some extent, a

vknuckle like oint.

I wish to make it distinctly understood that the two cylinder form of engine, I have depicted in Fig. 1, I have shown inerely to simplify the explanation of the operation of the essential parts of the engine. rlhe two cylinder form makes it feasible to show a vertical longitudinal section through the center of shaft and axes of cylinders and it is for this reason that it is shown.`

I do not consider the two cylinder engine forms a desirable embodiment of my invent1on. On the other hand, the four cylinder engine shown in Figs. 2 and 3 forms a preferred form of engine for the embodiment of my invention.v

I claim as follows;

l. In an engine, a revolving shaft, two wabbling knuckles mounted on the said shaft "on axes inclined to the main axis of the shaft and means preventing them from revolving with the shaft, a cylinder holding body comprising two parts, the: said shaft passing through the said cylinder holding body along the juijictionl of the said twoparts, cylinders in the said cylinder holding body arranged withitheir axes parallel to the axis of the said shaft, two istons reciprocating in each of the said cy inders, and connections between the said pistons and the said wabbling knuckles.

2. In an internal combustion engine, a revolving main shaft having two inclined crank pins, cylinders held parallel-to the axis of the said shaft, two pistons reciprocating in eachof the said cylinders, wabbling members mounted on each of the said two inclined crank pins, connections between the said pistons and the said wabbling knuckles, and valve gear shafts held parallel to the said main shaft and beingl geared to the said main shaft.

' `3. In an engine, a main shaft carrying two inclined crank pins, with wabbling members mounted on the said inclined crank pins, cylinders arranged substantially parallel to the said Shaft,`each of the said cylinders having two pistons reciprocating within it, the said cylinders being associated with a cylinder holding body made in two separable parts, the said main shaft passing through the said cylinder' holding body between the two said parts and connectionsbetween the said pistons and the said wabbling members.

4. In an engine, a horizontal main shaft carrying two inclined crank pins, with wabbling inembers mounted on the said inclined crank-pins, a cylinder holding body comprising a lower part and au ripper' part, the said parts being separable from each other, the said main shaft passing through the said cylinder holding body between the said upper and lower parts, cylinders substantially parallel tothe said shaft associated with the said cylinder holding body, two pistons reciprocating in each of the said cylinders and connections between the said pistons and the said wabbling members.

5. In an engine, a horizontal main shaft carrying two inclined crank pins, wabbling knuckles o r members mounted on the said crank pins, a cylinder holding body comprising a lower part and an upper part, the said vupperfpart being removable from the said lower part, the said main shaft passing through the said cylinder holding body between the said upper and lower parts and being held in bearings supportedby the said lower part, cylinders substantially parallel to the said shaft formed in or carried bythe said cylinder holding body, two pistons reciprocating 'in each of the said cylinders and connections between'the said pis-- tous and the said wabbling members.

6. In an engine, a horizontal 'main shaft carrying two inclined crank pins, wabbling knuckles or members mounted on the said crank pins, a cylinder holding body comprising a lower part and an upper part, the said upper part being removable from they said lower part, the said main shaft passing through the said cylinder holding body between the said upper and lower parts, four cylinders substantially parallel to the said shaft formed in or carried by the said cylinder holding body, two of the said cylinders being formed in or carriedv by the said upper part, and two of the said cylinders being formed in or carried' by the said lower part of the said cylinder holding body, two pistons reciprocating in each of the said cylinders and. connections between the said pistons and the said wabbling IUCHIDCI'S.

7. In an engine, a main shaft comprising two inclined crank pins and a straight middle port-ion between the twov crank pins, the axes of rtliesaid crank pins intersecting the main axis of the shaft, the said crank pins having their outer ends or ends most distant from Ythe said middle portion of the shaft more distant in a radial direction from the shaft axis than their Opposite or inner ends, wabbling members carried on the said crankpiiis, open ended working cylinders surrounding and arranged substantially parallel to the said shaft between the` said crank pins., two pistons reciprocate i'ng in each of the said cylinders and connectioiis between the said pistons and the said wabbling members.

8. In an engine, a main shaft comprising two inclined crank pins and a straight mid'- dle portion between the two crank pins, the axes of the said crank pinsintersecting the main axis of the shaft, the two points of intersection of the shaft axis with the axes of the said crank pins being closer to the inner.

ends of the said crank pins than to their outer ends, or ends most distant 4from the said middle portion of the shaft, wabbling members carried on the said crank pins, open ended working cylinders surrounding and arran ed substantially parallel to the said shaft etween the said crank pins, two

pistons reciprocating in each of the saidj cylinders and connections between the said the said crank pins, a thrust collar on each of the said crank pins locatedbetween the said bearings of the said wabbling members, open ended working cylinders surrounding and arranged substantially parallel to the said shaft between the said crank pins, two pistons reciprocating in each of the said cylinders and connections between the said pistons and the said wabbling members.

10. In an engine, a main shaft comprisino two inclined crank pins and a straight middle portion between the two .crank pins, the axes of the said crank pins intersecting outer ends, or ends, most distant from the said middle portion of the shaft,l a wabbling member` carried by two bearings on each of the said crank pins, a thrust collar on each of the said crank .pins located between the said bearings of the said wabbling inem: bers, .eachof the said thrust collars being made in two halves and clamped to the said crank pins, open ended working cylinders surrounding and arranged substantially parallel to thesaid shaft between the said crank pins, two pistons reciprocating in each `of .the said cylinders and connections between tlie said pistons and the said wabbling members.

11. In an engine, a main shaft compris ing twoinclined crank pins and a straight middle portion between the two crank pins,

the axes of the said crank pins intersecting the main axis of the shaft, a wabbling meinber carried by two bearings on each of the said crank pins, a thrust collar on each of the said crank pins located between the said bearings and the said wabbling members, shoulders on the said crank pins, each of the said thrust collars bearin against the said shoulders and being made in halvesV and clamped to the said crank pins, open ended working cylinders surrounding and arranged substantially parallel to the said shaft between the said crank pins, two istons reciprocating in each of the said cy inders and connections between the said pistons and the said wabbling members.

12. In an engine, a main shaft comprising a middle portion, a crank pin at each end of the said middle ortion and aibearing outside of each of t e said crank pins,

the said crank pins being inclined at an angle to the axis of the shaft and connected at their inner ends with the said middle portion of the shaft by short connections and with the bearings at their outer ends by suitable crank arms, wabbling members carried on the said crank ins, open ended working cylinders surroun ing and arran ed substantially parallel to the said shaft etween the said crank pins, two pistons reciprocating in each of the said cylinders and connections between the said pistons and the said wabbling members.

13. In an engine, a main shaft comprising `two inclined crank. pins and a straight middle portion between the two crank pins, the axes of the said crank pins intersecting the main axis of the shaft, open ended working cylinders surrounding and arranged substanti ally parallel to the said shaft between the said crank pins, two pistons reciprocating in each ofthe said cylinders, a wabbling knuckle or member carried on twowbearngs on each of the said crank pins, a thrust collar carried on each of the said crank pins between the saidbearings of the wabbling knuckle, connecting rods connecting the said pistons with the said wabbling knuckles or members, the said connectin rods having ball ends which bear in sp erical sockets formed in the wabbling knuckles, each of the said wabbling knuckles having a chambered recess formedin it between-its said two bearings on the crank pins, the said chambered recess having a portion of maximum inside diameter which said portion is located back of or beyond the centers of the said spherical sockets, in av direction away from the cylinders.

axis but normal or perpendicular to the axes of the crank pins, wabbling members carried on the said crank pins, open ended working cylinders surrounding and arranged substantially parallel to the said shaft between the said lcrank pins, twoL pistons reciprocating in each of the said cylinders and connections between the said pisvtons and the said wabbling members.

15. In an engine, a main shaft comprising a straight cylindrical center portion, having ends of enlarged diameter, the outer faces of which are formed by planes oblique to the main shaft axis, two crank pins having their axes perpendicular to the said oblique planes and joining the said center portions on the said oblique planes, two crank arms atthe outer ends of the said crank pins-and two end journals connected to and outside of the said crank arms, wabblingmembers carried onthe said crank pins, open ended working cylinders surrounding and arranged substantially parallel to the said shaft between the said crank pins, two pistons reciprocating in each of the said cylinders and connections between the said pistons and the said wabbling members.

16. In an engine, a main shaft comprising two inclined crank pins and a straight middle portion between the two crank pins, the axes of the said crankpins intersecting the main axis of the shaft, a wabbling member carried on two bearings on each of the said 'crank pins, a thrust collar carried on each of the said crank pins between the said bearings of the wabbling member, each of the said wabbling members beingmade in two separable p arts, each part forming an a proximate half and being recessed for e accommodation of the said thrust collars within it and connections between the said pistons and the said wabbling members.

17. In a-n engine, a main shaft comprising two inclined crank pins and a straight middle portion between the two crank pins, the axes of the said crank pins intersectino' the main axis of the shaft, open ended wor ing cylinders surrounding and arranged suhstantially parallel to the said shaft between the said crank pins, two pistons reciprocating in each of the said cylinders, a wabbling member carried on two bearings on each of the said crank pins, av thrust collar carried on each of the said crank pins between the said bearings of the wabbling member, each of the said wabbling members being made in two halves united by a flanged joint and being recessed for'the accommodation of the said thrust collars within it, and connections between the said pistons and the said wahbling members.

18. In an engine, a main shaft comprising two inclined crank pins and a straight middle portion between the two crank pins, the axes of the said crank pins intersecting the main axis of the shaft, =open ended working cylinders surrounding and arranged substantially parallel to the said shaft between the said crank pins, two pistons reciprocatingin each of the said cylinders, a wabbling knuckle carried on two bearings on each of the said crank pins, a thrust collar carried on each of the said 'crank\pins between the saidfbearings of the wabbling knuckle, connecting rods engaging with the said pistons at their inner ends and having ball shaped outer ends, the said wabbling knuckles beingrecessed for the accommodation of the said thrust collars and being made in two separaf ble parts, each part forming an approximate Vhalf and each of the two parts carrying an crank pins, a thrust collar carried on each of the said crank pins between the said bearings f the wabbling knuckle, each of the said wabbling knuckles being made in two separable parts, each part formin an approximate half and being recesse for the accommodation of the said thrust collars within it, each half of each of the said wabbling knuckles having connection with an equal number of connecting rods, each of said rods connecting-'in turn with one of the said pistons in one of the said working cylinders.

20. In an engine, a main shaft comprising two inclined crank pins and a straight middle portion between the two crank pins, the axes of the said crank pins intersecting the main axis of the shaft, open ended working part forming an approximate half, the said two parts of each knuckle being united bya joint lying in a plane passing through the axis of the crank pins and connections between the said pistons and the said wabbling members. 1

21. In an engine, a main shaft comprising two inclined crank pins and a straight mi dle portion between the two crank pins, the axes of the ,said crank pins intersecting the main axis of the shaft, open ended working cylinders surrounding and arranged substantially parallel to the said shaft between the said crank pins, two pistons reciprocating in each of the saidv cylinders, a wabbling knuckle or member carried on two bearino's on each of the said crank pins` a thrust co lar carried on each of die said crank ins between the said bearings of the wabb ing knuckle, each of the said wabbling knuckles being made in two separable parts, each part forming an approximate half and being recessed for the accommodation of the said thrust collars within it, a number of separate bearing shoes carried by each of the said wabbling knuckles, the said shoes bearing against the said thrust collars and connections between the said pistons and the said wabbling members.

22. In an engine, a main shaft comprising two inclined crank pins and a straight -middle portion between the two crank pins, the axes of the said crank pins intersecting the main axis of the shaft, open ended working cylinders surrounding and arranged substantially parallel to the said shaft between the said crank pins, two pistons reciprocating in each of' the said cylinders, a wabbling knuckle or member carried on two bearings on each ofthe said crank pins, a thrust collar carried on each of the said crank pins between the said bearings of the wabbling knuckle, each. of the said thrust collars bein made in two halves and clamped to the said crank pins, and each of the said wabbling knuckles being made in two separable parts, each part forming an approximate half and being recessed for the accommodation of the said thrust collar within it, a number of se arate bearing shoes carried by each of t e4 said wabblin knuckles, the said shoes bearing against t ie said thrust collar, and connections between the said pistons and the said wabbling members.

23. In an engine, a main shaft comprising two inclined crank pins and a straight middle portion between the two crank pins, the axes of the said crank pins intersecting the main axis of the shaft, open ended working cylinders surrounding and arranged sub' stantially parallel to the said shaft between the said crank pins, two pistons, reciprocating in each of the said cylinders, a wabbling knuckle or member carried on two bearings on each of the said crank pins, a thrust cdllar carried on 'each of the said crank pins between the said bearings of the wabbling knuckle, the said thrust collars being so placed on the crank pins that their bearing faces are a definite distance outward from the points of intersection of the axes of the crank pins with the axis of the shaft, measured axially along the pin in the direction away from the cylinders, and connections between the said pistonsand the said wabbling members.

24. In an engine, a main shaft comprising two inclined crank pins and a straiht middle portion between the two crank pms, the axes of the said crank pins 'intersecting the main axis of the shaft, open ended working cylinders surrounding and arran ed substantially parallel to the said shaft etweeln the said crank pins, two pistons reciprocating in each of the said cyllnders, a wabbling knuckle or member carried on two bearin s on each of the said crank pins, a thrust co lar carried on each of the said crank between the said bearings of the wabb ing knuckle, each of the said wabbling knuckles orL members having a chambered recess formed in it between its said two bearings on the crank pins, the said chambered recess having a portion of maximum inside diameterwhich said portion is located beyond the point of intersection of the crank pin axis with the axis ofthe shaft, measured axially along the pin in the direction away from the cylinders and connections between lle said pistons and the said wabbling memers.

25. In an engine, a main shaft com rising a straight cylindrical center portion,i aving ends of enlarged diameter, the outer faces of which are formed by planes oblique to the main shaft axis, two crank pins having their axes perpendicular to the said oblique planes and joining the said center portions von the said oblique planes, two crank arms at the outer ends of the said crank pins and two end Journals connected to and outside of the said crank arms. Y A

ins

26. in an engine, the combination of a shaftcarrying two crank axes inclined to the axis of the shaft, a cylinder holding body, the said shaft passing through the said cylinder holding body, cylinders substantial- 1y parallel to the said shaft formed or held in the said cylinder holding?)- body, Wabblinf;` members or knuckles mounted on the said inclined crank axes. two side iframes attached to and extendingbeyond the ends of the said cylinder holding body, a base plate attached to and connecting the tuo said side frames, guides attached to the sai d base plate, a guiding means attached to each of the said 15 Wabbling members or knuckles, the said guiding means engaging With the said guides attached to the base plate, pistons in the said cylinders connect-ing with the said wabbling members.

27. In an engine, the combination oa horizontal shaft carrying two inclined crank axes intersecting the axis of the shaft, Wabbling members or knuckles mounted on the said inclined crank axes, a cylinder holding;l body comprising an upper and a lower part, the said shaft passing through the said cylinder holding body ,between the said upper and lower parts, two cylinders formed in the said lower part of the said cylinder holding body, pistons in the said cylinders connect- :i

ing with the said Wabblingmembersntwo side frames attached to and extendiiw befond the ends of the said cylinder holding ody, a base Aplate attached to and connecting the two sald side frames, guides attached to the said base plate and below the said shaft, the said guides 'being located cen traIly, relative to an extension of the axes of the said two cylinders, and a guiding means attached to each of the said Wabbling members or knuckles, the said guiding means engaging with said guides attached to the base plate. i

In witness whereof, I hereunto subscribe my name this 20th day of December, 1924. GEORGE K. DAVGL. 

